(a) Field of the Invention
The present invention relates to a driving voltage generating circuit and a display device including the same.
(b) Description of Related Art
In recent times, flat panel displays such as organic light emitting diode (“OLED”) displays, plasma display panels (“PDPs”), and liquid crystal displays (“LCDs”) have been widely developed to replace the heavy and large cathode ray tubes (“CRTs”).
The PDPs are devices which display characters or images using plasma generated by a gas-discharge. The OLED displays are devices which display characters or images by applying an electric field to specific light-emitting organics or high molecule materials. The LCDs are devices which display images by applying an electric field to a liquid crystal layer disposed between two panels and regulating the strength of the electric field to adjust a transmittance of light passing through the liquid crystal layer.
Among the flat panel displays, as examples, the LCD and the OLED display each includes a panel assembly provided with pixels including switching elements and display signal lines, a driving voltage generator generating driving voltages, a gate driver providing a gate signal for gate lines of the display signal lines to turn on/off the switching elements, a gray voltage generator generating a plurality of gray voltages, a data driver providing a data signal for data lines of the display signal lines to apply a data voltage to the pixel via the turned-on switching elements, and a signal controller controlling the above-described elements.
The above-described elements are applied with predetermined voltages to be converted into voltages required for driving the specific circuitry. For example, the gate driver is applied with a gate on voltage and a gate off voltage from the driving voltage generator for application to the gate lines as the gate signals, and the gray voltage generator is applied with a predetermined reference voltage from the driving voltage generator for dividing into a plurality of voltages via resistors and then providing the divided voltages for the data driver.
However, the gate-on voltage and the gate-off voltage are not generated independently of the reference voltage applied to the gray voltage generator, and thus accurate gate signals required for driving may not be supplied for the gate driver.